Power supply swap / put 540 ps in a 240

The power supply in my 240 up and died on me last night. I've been searching for a cheap replacement and I did find some on ebay. However, there are power supplies for several models currently listed, but the prices vary a lot. One listing states that the ps will work in the 240 and 540 models as well as a few other models. That one would cost me about $45. There's another listing for a ps for a 540 that would cost me $21, but I may be able to get my hands on a 540 power supply for free. So the question is - Can I use a power supply from a 540 to replace the bad one in my 240?

I've tried something similar, with unsuccessful results. I tried to use a DirecTV R10 power supply in a DirecTV Series2. A DTV R10 is the DTV version of the 540 hardware, while the DTV Series2's are the equivalent to the 140/240's.

When I tried it, it did not work, but the test failed without damaging anything...it was a simple "nothing happened" failure.

The power supply in my 240 up and died on me last night. I've been searching for a cheap replacement and I did find some on ebay. However, there are power supplies for several models currently listed, but the prices vary a lot. One listing states that the ps will work in the 240 and 540 models as well as a few other models. That one would cost me about $45. There's another listing for a ps for a 540 that would cost me $21, but I may be able to get my hands on a 540 power supply for free. So the question is - Can I use a power supply from a 540 to replace the bad one in my 240?

Thought I would add my question here instead of starting a new thread. I think I know the answer, but here goes -

I have a lifetimed series 2 240. I also have an unused (no svc subscrp)series 2 540. Would the harddrive from the 540 work if I put it into the 240, which needs a new harddrive, without having to go thru the trouble of changing the 540's image to a 240 image?